On 2/26/20 10:05 AM, Catalin Marinas wrote: > + /* > + * From include/uapi/linux/prctl.h > + */ > + #define PR_SET_TAGGED_ADDR_CTRL 55 > + #define PR_GET_TAGGED_ADDR_CTRL 56 > + # define PR_TAGGED_ADDR_ENABLE (1UL << 0) > + # define PR_MTE_TCF_SHIFT 1 > + # define PR_MTE_TCF_NONE (0UL << PR_MTE_TCF_SHIFT) > + # define PR_MTE_TCF_SYNC (1UL << PR_MTE_TCF_SHIFT) > + # define PR_MTE_TCF_ASYNC (2UL << PR_MTE_TCF_SHIFT) > + # define PR_MTE_TCF_MASK (3UL << PR_MTE_TCF_SHIFT) > + # define PR_MTE_TAG_SHIFT 3 > + # define PR_MTE_TAG_MASK (0xffffUL << PR_MTE_TAG_SHIFT) Is there a reason not to include TCMA into the set of bits that userland can control with this prcrl? I know that ordinarily TCR_ELx requires expensive syncing, but for this particular field there is a note about "software may change this control bit on a context switch". Which I take to mean that the usual TLB-related syncing may be omitted. r~
